A conventional windshield wiper is constituted by a wiper arm (1) and wiper blade (2) as illustrated in FIG. 1. Mostly, the wipers are exposed to the outdoors so that the wiper blades (2) will be stained with dust and dirt or even oily stains from the polluted air as the car is running or parked on the street. Consequently, as the car is running in the rain and the wiper is needed, the dust and stains may considerably decrease the wiping effect of the wiper. It is obvious that, no matter whether or not the wiper is in use, as long as it has been equipped on the car for a short period of time, proper wiping may not occur and put the driver at risk of having obscured vision as he drives. Some drivers may clean the wiper blade from time to time, while others may just replace with new wipers. Either way, there is undesirable waste of time or expense.